How important is sitting behind a load balancer?

I ran it with the Profiler. It take 3.4 secs to run the report. I have split off a part that preps the database files prior to running the reports and that takes about 1.1 sec. I am running CI 3.

I am just not sure about how CI runs. Will other users be blocked while a 3.4 second report is running?

I already spent a bunch of time modifying my system to use RDS but i am running out of gas to use S3 for the images.

proof that an old dog can learn new tricks